Die-stock.



R. BARTHOLUMEM DIE STBGK.

APPLIOLTIDX FILED 66123;.m?.

Patne@ sept. 1 5, 190s'.

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RUDOLF B iRTnoLonUs, OF DRESDEN, GERMANY.

Drs-STOCK.

Specification of Letters Patenti Patented Sept. 15, 1908.

Application filed October 3, 1907. Serial No. 395,723.

To all whom it may concern.'

Be it known that I, RUDOLF BARTHOLO MUS, a subject of thc German Emperor, residing at Dresden, Saxony, German Empire, have invented certain new and useful Im- Y provements in Die-Stocks, of which the folowing is a specification.

My invention relates to improvements in stocks and dies employed in screw cutting.

By means of my new tool threads of various sizes can be cut without the dies having to be removed each time from the stock and replaced by others.

My invention is illustrated in the accompanying drawing, in which- Figure 1 is a vertical section through the tool. Fig. 2 is a section on the line A-B of Fig. 1. Fie. 3 is a part sectional view of the device employed for setting the dies.

In the casing or box a of the stock there is screwed a disk b provided with radial guidegrooves to receive the dies c, which slide therein and have inclined recesses s. The box o also contains a collar d, which presents three splayed feet e and carries above a. guide-socket The latter is furnished with twoinclined grooves g, h, each running half i7 way round the socket. VOn the top of the box a there is a ring i, capable of being turned horizont ally to and fro by the handle 1c. T his rino has two inwardly projecting pins, one of willich l is shown in Fig. 1. This pin l engages in the groove g of the socket f, while the twin" pin (not shown in the drawing) takes into the other groove h. It is obvious that on rotation to and fro of the ring i bv means of the handle k, the socket f with its kcollar d will be moved up and down, the extcnt'of motion depending upon the inclination of the grooves g, h Screwed into the c. lVhen the collar cl is now caused to descend, by rotation of the ringe ifi its handle 7c, the feet e enter the inclined recesses s provided in the dies c and Jforce the latter inward, so as to bring them into their operative screw cutting position.

To enable accurate adjustment of the colnotches o corresponding in number to the number of kinds of threads to be cut. The particular tool shown has four sets of three dies each for cutting four different threads of diflerent pitch, wherefore the tube n has four notches o. From the inner wall of the socketf there projects a stud p, adapted to t the notches 0. Thus if the tool be set for cutting a certain thread, the collar d must be rotated by the ring m until the stud p arrives above the notch o which corresponds to the thread in question. Gn rotation of the ring i by turning the handle lc the stud p then slips into this notch o and thus holds the collar d in a definite position. Then one set of Adies is adjusted for work, the other sets remain in their outer, inoperative position, the dies being fitted into the radial guide-grooves nith sulicient frictional contact to hold them against inward-sliding, especially when in operation, there being also at that timea slight centrifugal action to reinforce said rictional contact. The dies having been thus adjusted, the tool can be employed like any ordinary screw stock.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is- 1. A die stock, comprising a radially perforated box, a plurality of sets of dies slidable in the )erforations thereof, said dies having beveled portions, a collar having splayed feet to engage the beveled vportions of the dies and mounted in the bo: to move ixially, said collar being also rotatably adjustable to engage selectively with diierent sets of dies and means for moving the collar axially.

2. A die stock comprising a radially perforatcd box carrying an upright tube with top of the socket there 1s a. ring m, by turning which the co ar d can be so set that its of dies slidable in the perforations ofthe nox, feet e come above any des1red group of dies notchesin its upper edge, a plurality ci sets said dies having beveled portions, a cellar having splayed feet to engage the beveled portions ofthe dies and an inward projection to engage the notches of said tube, said collar being mounted to move axially and being rotatably adjustable to engage selectively with different sets of dies, and means for moving the collar axially.

' lar d, a guide-tube n is providedin the box a. 3. A die stock comprising a radially per- This tube n fits into the socketf and 1s furforated boit carrying an upright tube with 105 nished at its upper edge with e series of i notches in its upper edge, a plurality of sets and provided with inward projections to cn- 2 Y s9s,9se"f""ff of dies slidable inthe perforetions of the box', I gage in said slots, and mea-ns for rotating the said dies having beveled portions, a collar g ring whereby the collar is axially moved. 10 having splayed f eet to engage the beveled l In testimony whereof I affix mysignature portions of the dies, an inward projection to g in presence of two witnessrm`V engage the notches and an upper tubular ex- RUDOLF 'BARTHOLOMAUS tension having spirally located slots, :L ro- Vitnesses: l

tary ring encircling the tubular extension PAUL ARRAS,

CLARE SIMON. 

